My 1DMK3 has been throwing out an "Err99" message on startup. I can get things working by turning the camera off, then removing and reinstalling the battery. Turn it on after doing this and it's best kind.

I've done all the usual remedies like cleaning contacts, trying different lenses, reinstalling firmware, reinstalling the date & time battery and the Err 99 persists.

Just wondering if anyone else had this problem and if so did it get worse?
It's busy season for me so I'd keep doing the battery reset just to get me through a couple more weeks .. unless someone tells me that in their experience it's only going to get worse

Otherwise, you can upgrade to latest firmware and it should give you more info about "whats wrong". Err99 usually meant its mirror issue (needs to be fixed by Canon, sorry), but ofc it might mean something else, unfortunately beyond our reach to find out "what is wrong".

Otherwise, you can upgrade to latest firmware and it should give you more info about "whats wrong". Err99 usually meant its mirror issue (needs to be fixed by Canon, sorry), but ofc it might mean something else, unfortunately beyond our reach to find out "what is wrong".

It might or might not go worse. I wouldnt push it personally..

Thanks .. It's a yellow dot, and I did buy it used. It had 1.23 firmware and I upgraded to 1.3 a few days after first noticing the Err99 thinking that it may clear the problem, but it didn't.

And I think you're right about it being a mirror issue as after getting the message and turning the camera off the mirror goes up (like it would with MLU or sensor cleaning) .. then goes down again when you turn it back on.

And it does not have any problems on startup with no lens attached .. it just starts right up and works fine.

Mike Mahoney wrote:
Thanks .. It's a yellow dot, and I did buy it used. It had 1.23 firmware and I upgraded to 1.3 a few days after first noticing the Err99 thinking that it may clear the problem, but it didn't.

And I think you're right about it being a mirror issue as after getting the message and turning the camera off the mirror goes up (like it would with MLU or sensor cleaning) .. then goes down again when you turn it back on.

And it does not have any problems on startup with no lens attached .. it just starts right up and works fine....Show more →

No lens attached without problem? Hm, might be some problem in AF circuit, but its just wild guess.

Have you tried fast shutter speeds at high f-stop? 1/8000 at f11-f16 - It can sometimes show if shutter is fine or not. If theres light-streak across pic, its dying shutter. But I think it doesnt work always, just saw it few times.

Here's something .. I realized that I had been only using two lenses during my Err99 period, those being a 70-200 IS and the 24-105 IS. I also cannot get the Err99 with just a body cap on (no lens attached) .. and after reading the Lens Rental Err99 write up which suggests that many Err99 causes are battery voltage and or / lens voltage requirement drain related I decided to put a non IS lens on, my Sigma 85 1.4 and voila .. no Err99 at all.

So it seems a voltage issue or a lens issue .. both are not likely as my batteries are new and fully charged and the chances of two lenses developing problems at the same time are pretty small. I'll clean battery contacts just to be sure.

If it's still up, and I don't see it listing an expiry date, you should point it out to them, as it was a recall and they should still honor it. They did try to get out of fixing one of mine back in Aug. 2009 saying the actuations on my camera were on the high side, but they did indeed fix it for no charge.

It's possible though that there could be more than one problem that triggers the Err99 code.

If it's still up, and I don't see it listing an expiry date, you should point it out to them, as it was a recall and they should still honor it. They did try to get out of fixing one of mine back in Aug. 2009 saying the actuations on my camera were on the high side, but they did indeed fix it for no charge.

It's possible though that there could be more than one problem that triggers the Err99 code.

Thank you for that! .. I knew I had seen it but the lady at Canon assured me that there were no current 1DMK3 Err99 recalls.

That is no longer the case with the latest firmware (I have 1.2.5 in my 1D Mk III). Error 99 was split up into half a dozen codes starting with 80, and rather foolishly reusing 99 as a specific error. I don't have a bookmark handy on this machine, but I think they are listed in the firmware release notes. Error 99 now means the shutter can't complete its cycle.

If you don't have the latest firmware I'd put it on there. And I'd do it with the AC adaptor rather than the battery if you have that (it came with my camera new).

I've had an Error 99 in one session and it was caused by a bad battery. That battery (genuine Canon and less than a year old) was known to have high self-discharge on another body and barely gave 500 shots on the other body. On this occasion, I was tracking a bird in AI servo at high frame rate with a super-tele, converter, IS running, early in the morning in 4°C. A quick search showed that the shutter sometimes can't complete its cycle if the power sags in the middle.

Clearing the fault with a good battery did require removing the CF card and cycling the shutter without it ("shoot without CF card on"). This was part of the Canon diagnostic procedure I found on their site.

So it's been a day's shooting with a Sigma 85 1.4 and zero problems .. startup is fine, no Err99.
And while it seems unlikely that two lenses (both IS) would be giving problems at the exact same time that is certainly a consideration since the error code only shows when those two lenses are used.

Normally I would just send to Canon but it's my busy season and although I've other bodies and backups I'll wait a month or so and send in then. In the meantime I'll avoid using the two lenses that gave the error code.

My suspicion is an electrical or battery power malfunction of some kind.
Thanks again